Rice hulls, a byproduct in the preparation of rice grains, has found many uses. One particular use is as a cleaning scouring abrasive in mechanics' handsoaps, wherein the rice hulls are ground to pass 20 mesh but not 100 mesh, in amounts of 10-25% by weight of the soap composition, as disclosed in chapter 12 page 331 of Rice Chemistry and Technology, Edited by D. F Houston, published by American Association of Cereal Chemists, Inc., St. Paul, Minnesota, 1972. Another use for finely ground hulls, described on page 332 of the same book, is as a filler in plastics and plywood glues. Still another use is as a carrier or adsorbent for materials ranging from vitamins to pesticides to explosives. However, there is no disclosure of the use of finely ground rice hulls as a powder base for body powders.
Talc, a natural hydrous magnesium silicate, is the major ingredient used today in body powders. However, talc has low water absorption properties and has been found irritating to the tender skins of babies. Accordingly, corn or rice starch has been substituted for talc as a dusting powder as shown in U.S. Pat. No. 2,469,957. Handbook of Cosmetic Materials, by Leon A. Greenberg and David Lester (1954) pages 303 and 304 also describes the starches including rice starch and their uses in dusting powders and face powders, as well as their possible adverse dermatological reactions. The use of rice starch in bath powders and face powders, as well as possible problems encountered therewith, is also disclosed in Cosmetics Science and Technology, Second edition, Vol. 2, edited by M. S. Balsam and Edward Sagarin (1957), pages 515 and 339. Riechstoffe Seifen Kosmetika by H. Janistyn, Vol. 1 (1950) page 372 also discloses rice starch which is obtained from fragmented rice, as a raw material for cosmetics. Starches generally, and rice starch specifically, as a constituent of face powder is disclosed in The Chemistry and Manufacture of Cosmetics by Maison G. de Navarre, (1981) page 337. Thus, it is apparent from the prior art that rice starch has been substituted for part or all of the talc in a body powder composition in order to eliminate some of the deficiencies of talc. However, additional problems have arisen from the use of starches as aforedescribed, and the major deficiency of insufficient moisture absorbency of said powders is still existent.
The prior art also discloses face powders containing small amounts of a special fraction of dehulled oat groats ground to 60-70 mesh, in U.S. Pat. No. 2,436,818; and face powders containing large amounts of walnut shell flour as filler, in U.S. Pat. No. 4,279,890.
Although the prior art discloses rice starch which is an extract from rice grains, and dehulled oat grains, and walnut shell flour as an ingredient in body powders, there is no disclosure of rice hulls, a byproduct in the preparation of rice grains. More specifically, rice grains are obtained by first dehulling and then debranning the rice product. Finely ground rice hulls as the powder base for high absorption body powder is the subject matter of this invention.